Abstract: With consideration of nonuniform skin effect factor, the mathematical model for 3D radial flow for anisotropic confined aquifer is presented. To attain solution for the corresponding problem, the skin effect factor is deemed as piecewise continuous functions, according to which the confined aquifer is divided into N layers. Then the method of finite difference is used to transfer the original problem into matrix differential equation with boundary conditions; and finally, by matrix theory, the solution is attained. With mathematical software, the solution is applied to numerical examples. Results show that: In the region close to vertical well, the variation of drawdown and flux component is inversely related to the skin effect factor; that is, larger skin effect factor leads to smaller drawdown and flux, vice versa, while in the region far from vertical well, the same tendency of variation keeps only for the situation that vertical permeability is far smaller than radial permeability. Therefore, the amplitude value of the curves s*- r* for different layers of confined aquifer depends on both the value of skin effect factor and the ratio of vertical permeability to radial permeability.

Key words: skin effect factor, mathematical model, matrix differential equation, finite difference method, confined aquifer